August, '17] TUCKER: PEGOMYIA FUSCICEPS AND FIELD CROPS 397 



plants in the field. Thej^ were subsequently placed on healthy beets 

 grown from seed in insect-proof cages. The condition was produced 

 in four experiments. 



Insects known to be virulent were placed on healthy seedlings 

 of Malva rotundifolia. After a certain lapse of time they were removed 

 and replaced with non-virulent insects which were later transferred 

 to healthy beets. All transfers brought about the disorder. 



These discoveries throw considerable light on the nature of the 

 condition of sugar beets called curly-top, and establish beyond doubt 

 the possibility of preventing or limiting injury by this condition 

 through the control of the leafhoppers affecting the beets, and through 

 the establishment of clean cultural methods, by means of which 

 infected plants which act as hosts to the leafhoppers may be removed 

 from the vicinity of beet fields. 



RELATION OF THE COMMON ROOT MAGGOT (PEGOMYIA 

 FUSCICEPS ZETT.) TO CERTAIN CROPS IN LOUISIANA 



By E. S. Tucker, State Agricultural Experiment Station, Baton Rouge, La. 



Attacks on Young Tomato Plants 



A number of injured tomato plants ranging from five to six inches in 

 length and a few specimens of a small maggot said to have been found 

 burrowing in the stems of similar growth were brought to the writer 

 for examination on March 3, 1914, bj^ a merchant of Norwood, East 

 Feliciana parish. La. He stated that a gardener of his home town had 

 lost more than 1,000 plants like the samples, from stock grown under 

 culture in a coldframe, all having failed in the short time of about 

 two days. When the bed was covered on Saturday evening, February 

 28, the growth appeared to be perfectly healthy; but on opening the 

 frames on Monday, March 2, the owner noticed many drooping plants, 

 and by close examination, determined the cause of damage through 

 discovery of some maggots in the stems. Other growers also com- 

 plained that their beds were likewise being depleted. 



The sudden loss of great numbers of plants in such manner naturally 

 excited some alarm among the growers, who feared that the trouble 

 might become more extended and thus restrict their production of a 

 tomato crop for the approaching season. Since none of the gardeners 

 had ever before known an eneni}' of this kind to do any harm to 

 tomato plants, the question of its identity and life-history, and how 

 to deal with it, presented an entirely new problem. For the benefit of 

 the community, therefore, the merchant hastened on a visit to consult 



